U.S. patent application number 13/421161 was filed with the patent office on 2012-10-04 for solid-state imaging device and electronic apparatus.
This patent application is currently assigned to SONY CORPORATION. Invention is credited to Kyoko Izuha, Nozomi Kimura, Toshiyuki Kobayashi, Keisuke Shimizu.
Application Number | 20120249829 13/421161 |
Document ID | / |
Family ID | 45999521 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120249829 |
Kind Code |
A1 |
Izuha; Kyoko ; et
al. |
October 4, 2012 |
SOLID-STATE IMAGING DEVICE AND ELECTRONIC APPARATUS
Abstract
A solid-state imaging device includes: a substrate; a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; and a transparent electrode that is formed in an
upper portion of the substrate and includes a first area formed
from a nano carbon material and a second area that is brought into
contact with the first area and has light transmittance higher than
that of the first area.
Inventors: |
Izuha; Kyoko; (Kanagawa,
JP) ; Shimizu; Keisuke; (Kanagawa, JP) ;
Kobayashi; Toshiyuki; (Kanagawa, JP) ; Kimura;
Nozomi; (Kanagawa, JP) |
Assignee: |
SONY CORPORATION
Tokyo
JP
|
Family ID: |
45999521 |
Appl. No.: |
13/421161 |
Filed: |
March 15, 2012 |
Current U.S.
Class: |
348/229.1 ;
250/208.1; 348/222.1; 348/E5.031; 348/E5.037 |
Current CPC
Class: |
H01L 27/14685 20130101;
H01L 27/14625 20130101; H01L 27/14806 20130101; H01L 27/14623
20130101; H01L 27/14643 20130101; H01L 27/14621 20130101 |
Class at
Publication: |
348/229.1 ;
348/222.1; 250/208.1; 348/E05.037; 348/E05.031 |
International
Class: |
H04N 5/235 20060101
H04N005/235; H01L 27/146 20060101 H01L027/146; H04N 5/228 20060101
H04N005/228 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2011 |
JP |
2011-072177 |
Dec 12, 2011 |
JP |
2011-271364 |
Claims
1. A solid-state imaging device comprising: a substrate; a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; and a transparent electrode that is formed in an
upper portion of the substrate and includes a first area formed
from a nano carbon material and a second area that is brought into
contact with the first area and has light transmittance higher than
that of the first area.
2. The solid-state imaging device according to claim 1, wherein the
second area is formed from a gap, graphene oxide, or a transparent
polymer material.
3. The solid-state imaging device according to claim 2, wherein the
second area is formed from a gap, and an opening diameter of the
gap is smaller than an area of a unit pixel.
4. The solid-state imaging device according to claim 3, wherein a
width of a narrowest portion of the first area is larger than 10
nm.
5. The solid-state imaging device according to claim 2, wherein a
dimming control laminated film that adjusts a light amount of light
incident to a light incident side of the substrate is formed, and
wherein the dimming control laminated film is configured by a
dimming control reacting material layer of which transmittance
changes based on an applied voltage and first and second
transparent electrodes that hold the dimming control reacting
material layer therebetween, and at least one of the first and
second transparent electrodes is configured by the transparent
electrode that is formed from the nano carbon material.
6. The solid-state imaging device according to claim 5, further
comprising: a color filter layer and an on-chip lens that are
formed in order from the light incident light side of the
substrate, wherein the dimming control laminated film is arranged
to the light incident side relative to the on-chip lens.
7. The solid-state imaging device according to claim 5, further
comprising: a color filter layer and an on-chip lens that are
formed in order from the light incident side of the substrate,
wherein the dimming control laminated film is formed between the
substrate and the color filter layer.
8. The solid-state imaging device according to claim 5, wherein an
accumulated charge detecting circuit that detects signal charge
generated by the photoelectric conversion unit is connected to the
first transparent electrode, and wherein a voltage based on the
signal charge generated by the photoelectric conversion unit is
applied to the fist transparent electrode.
9. The solid-state imaging device according to claim 5, wherein the
first transparent electrode is formed to be separated for each
predetermined pixel.
10. The solid-state imaging device according to claim 5, wherein
the dimming control laminated film is formed only in an upper
portion of the photoelectric conversion unit that corresponds to
the predetermined pixel.
11. The solid-state imaging device according to claim 1, wherein
the transparent electrode is configured by a single layer or a
plurality of layers of a film-shaped nano carbon material.
12. The solid-state imaging device according to claim 1, wherein
the transparent electrode is configured by a plurality of layers of
film-shaped nano carbon materials, and the second areas of each
layer are laid out not so as to confront each other.
13. The solid-state imaging device according to claim 2, wherein
the gap formed in the transparent electrode is formed only in an
effective pixel area but is not formed in a black reference pixel
area.
14. The solid-state imaging device according to claim 5, wherein
the dimming control reacting material layer is configured by an
electrochromic material.
15. The solid-state imaging device according to claim 5, wherein
the dimming control reacting material layer is configured by a
liquid crystal layer.
16. The solid-state imaging device according to claim 1, wherein a
photoelectric conversion layer that generates signal charge
corresponding to light amount of light incident to a light incident
side of the substrate is formed, and wherein the photoelectric
conversion layer is configured by an organic photoelectric
conversion film that absorbs light of a predetermined wavelength
and first and second transparent electrodes that hold the organic
photoelectric conversion film therebetween, and at least one of the
first and second transparent electrodes is formed from a nano
carbon material.
17. The solid-state imaging device according to claim 1, wherein
the nano carbon material is graphene.
18. The solid-state imaging device according to claim 1, wherein a
desired additive is added to the transparent electrode.
19. An electronic apparatus comprising: an optical lens; a
solid-state imaging device that includes a substrate, a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light, and a transparent electrode that is formed in an
upper portion of the substrate formed from a nano carbon material
and has a plurality of openings, and to which light collected to
the optical lens is incident; and a signal processing circuit that
processes an output signal output from the solid-state imaging
device.
20. An electronic apparatus comprising: an optical lens; a
solid-state imaging device that includes a substrate and a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; an aperture diaphragm that is formed in an optical
path between the optical lens and the solid-state imaging device,
adjusts light beams transmitted from the optical lens, and is
configured by a dimming control reacting material layer of which
transmittance changes based on an applied voltage and first and
second transparent electrodes that hold the dimming control
reacting material layer therebetween; and a signal processing
circuit that processes an output signal output from the solid-state
imaging device, wherein at least one transparent electrode of the
first and second transparent electrodes is configured by a
transparent electrode that is formed from a nano carbon material
having a plurality of openings.
21. An electronic apparatus comprising: an optical lens; a
solid-state imaging device that includes a substrate and a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; a shutter device that is formed in an optical path
between the optical lens and the solid-state imaging device,
controls an exposure time toward the photoelectric conversion unit,
and is configured by a dimming control reacting material layer of
which transmittance changes based on an applied voltage and first
and second transparent electrodes that hold the dimming control
reacting material layer therebetween; and a signal processing
circuit that processes an output signal output from the solid-state
imaging device, wherein at least one transparent electrode of the
first and second transparent electrodes is configured by a
transparent electrode that is formed from a nano carbon material
having a plurality of openings.
Description
FIELD
[0001] The present disclosure relates to a solid-state imaging
device including a transparent electrode, an electronic apparatus
including the solid-state imaging device, and an electronic
apparatus including a transparent electrode.
BACKGROUND
[0002] A solid-state imaging device that is represented by a CCD
(Charge Coupled Device) image sensor or a CMOS (Complementary Metal
Oxide Semiconductor) image sensor includes a photoelectric
conversion unit that is configured by a photodiode formed on the
light receiving face side of a substrate and a charge transfer
unit. In such a solid-state imaging device, light incident from the
light receiving face side is photoelectrically converted by the
photodiode so as to generate signal charge according to the amount
of light. Then, the generated signal charge is transferred to a
charge transfer unit and is output as a video signal.
[0003] In such a device, since a structure is employed in which
light incident during an exposure time as a constant time interval
is photoelectrically converted and accumulated, it is necessary for
the photodiode to be open to the light receiving face side.
Accordingly, in a case where an electrode is formed in an area that
covers the light receiving face side of the photodiode, it is
necessary for the electrode to be formed not from a general
electrode material having a light shielding property but from a
transparent electrode material.
[0004] As disclosed in JP-A-08-294059 and JP-A-07-94699, indium tin
oxide (ITO) is mainly used as the material of a general transparent
electrode in the related art. In addition, as disclosed in
JP-A-2011-17819, in an electronic apparatus represented by a camera
or the like, there is an example in which a light control element
such as an electrochromic layer is used in an imaging optical
system such as an aperture diaphragm or a shutter device. Even in
such a case, as the material of a transparent electrode used for
applying a desired electric potential to the electrochromic layer,
ITO is used. However, ITO that is used as the material of the
transparent electrode has low transmittance in the current status,
and there are problems in that the sensitivity is decreased, and
the optical characteristics change due to a large film
thickness.
SUMMARY
[0005] It is desirable to provide a solid-state imaging device, in
which a transparent electrode is formed, capable of solving the
problems of a decrease in the transmittance of the transparent
electrode and variations in the optical characteristic due to the
film thickness. In addition, it is desirable to provide an imaging
apparatus and an electronic apparatus that use the solid-state
imaging device.
[0006] An embodiment of the present disclosure is directed to a
solid-state imaging device having a structure including: a
substrate; a photoelectric conversion unit that is formed on the
substrate and generates signal charge in correspondence with a
light amount of incident light; and a transparent electrode that is
formed in an upper portion of the substrate in which the
photoelectric conversion unit is formed, and the material of the
transparent electrode is a nano carbon material and has a plurality
of openings.
[0007] In the solid-state imaging device, by using the nano carbon
material having a plurality of openings as the transparent
electrode, the transmittance can be improved. In addition, since
the nano carbon material is used as a film of a single layer or a
plurality of layers, the film thickness is small, and a change in
the optical characteristics can be decreased.
[0008] Another embodiment of the present disclosure is directed to
an electronic apparatus including: an optical lens; a solid-state
imaging device to which light collected to the optical lens is
incident; and a signal processing circuit that processes an output
signal output from the solid-state imaging device. In addition, the
solid-state imaging device includes a substrate, a photoelectric
conversion unit that is formed on the substrate and generates
signal charge in correspondence with a light amount of incident
light, and a transparent electrode that is formed in an upper
portion of the substrate, is formed from a nano carbon material,
and has a plurality of openings.
[0009] According to the electronic apparatus, since the transparent
electrode that configures the solid-state imaging device is
configured by using a nano carbon material having an opening, the
transmittance is improved. Accordingly, an electronic apparatus in
which the image quality is improved can be acquired.
[0010] Still another embodiment of the present disclosure is
directed to an electronic apparatus including: an optical lens; a
solid-state imaging device that includes a substrate and a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; an aperture diaphragm; and a signal processing
circuit that processes an output signal output from the solid-state
imaging device. The aperture diaphragm that is arranged in an
optical path between the optical lens and the solid-state imaging
device and adjusts light beams transmitted from the optical lens.
In addition, the aperture diaphragm is configured by a dimming
control reacting material layer of which transmittance changes
based on an applied voltage and first and second transparent
electrodes that hold the dimming control reacting material layer
therebetween. Furthermore, at least one transparent electrode of
the first and second transparent electrodes is configured by a
transparent electrode that is formed from a nano carbon material
having a plurality of openings.
[0011] Yet another embodiment of the present disclosure is directed
to an electronic apparatus including: an optical lens; a
solid-state imaging device that includes a substrate and a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; a shutter device; and a signal processing circuit
that processes an output signal output from the solid-state imaging
device. The shutter device is arranged in an optical path between
the optical lens and the solid-state imaging device and controls an
exposure time toward the photoelectric conversion unit. In
addition, the shutter device is configured by a dimming control
reacting material layer of which transmittance changes based on an
applied voltage and first and second transparent electrodes that
hold the dimming control reacting material layer therebetween.
Furthermore, at least one transparent electrode of the first and
second transparent electrodes is configured by a transparent
electrode that is formed from a nano carbon material having a
plurality of openings.
[0012] According to the electronic apparatus of the embodiment, the
aperture diaphragm or the shutter device is configured by a dimming
control laminated film, and by changing the transmittance of the
dimming control laminated film, the operation of the aperture
diaphragm or the shutter device is performed. In addition, in the
dimming control laminated film, since at least one transparent
electrode of the first and second transparent electrodes is
configured by using a nano carbon material having a plurality of
openings, a decrease in the thickness of the dimming control
laminated film is achieved. In addition, the transmittance at the
time of light transmission can be improved.
[0013] According to the embodiments of the present disclosure, a
transparent electrode is formed from nano carbon having high
transmittance and has a plurality of openings, and accordingly,
maximum transmittance can be acquired. As a result, even in a case
where the transparent electrode is formed on the upper portion of a
photoelectric conversion unit, a decrease in sensitivity can be
prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates the whole configuration of a solid-state
imaging device according to a first embodiment of the present
disclosure.
[0015] FIG. 2 is a schematic cross-sectional view illustrating the
configuration of a main portion of the solid-state imaging device
according to the first embodiment of the present disclosure.
[0016] FIG. 3 is a schematic plan view illustrating the
configuration of a transparent electrode used in the solid-state
imaging device according to the first embodiment of the present
disclosure.
[0017] FIG. 4 is a diagram illustrating a change in the
transmittance of the transparent electrode in a case where the
diameter of an opening is fixed, and an electrode width is
changed.
[0018] FIG. 5 is a diagram illustrating a change in the resistance
of the transparent electrode in a case where the diameter of the
opening is fixed, and the electrode width is changed.
[0019] FIG. 6 is a schematic diagram illustrating the configuration
of the transparent electrode that is used when the transmittance
and the resistance with respect to the aperture ratio are actually
measured.
[0020] FIG. 7 is a result (1) of measurements of the transmittance
when the aperture ratio of the transparent electrode is changed in
the range of 0 to 87.5%.
[0021] FIG. 8 is a result (2) of measurements of the transmittance
when the aperture ratio of the transparent electrode is changed in
the range of 0 to 87.5%.
[0022] FIG. 9 is a diagram illustrating the resistance (the value
of an actual measurement) at a time when the aperture ratio of the
transparent electrode is changed in the range of 0 to 87.5% and the
resistance (theoretical value) of a transparent electrode having an
opening that is calculated by using Equation (3).
[0023] FIG. 10 is a diagram illustrating the resistance (the value
of an actual measurement) in a case where AuCl.sub.3 is added to
the transparent electrode and the resistance (theoretical value) of
the transparent electrode in a case where the addition of
AuCl.sub.3 is considered.
[0024] FIGS. 11A to 11D are process diagrams illustrating a method
of forming a transparent electrode that has an opening.
[0025] FIG. 12 is a schematic cross-sectional view illustrating the
configuration of a solid-state imaging device according to a second
embodiment of the present disclosure.
[0026] FIG. 13 is a schematic cross-sectional view illustrating the
configuration of a solid-state imaging device main body illustrated
in FIG. 12 in an enlarged scale.
[0027] FIGS. 14A and 14B are diagrams illustrating changes in the
transmittance of a dimming control laminated film with respect to
an applied voltage.
[0028] FIG. 15 is a diagram illustrating signal characteristics of
an output signal in the case of high sensitivity and an output
signal in the case of low sensitivity.
[0029] FIG. 16 is a diagram illustrating the range of illumination
in which imaging can be performed.
[0030] FIG. 17 is a schematic cross-sectional view illustrating the
configuration of a main portion of a solid-state imaging device
according to a third embodiment of the present disclosure.
[0031] FIG. 18 is a schematic cross-sectional view illustrating the
configuration of a main portion of a solid-state imaging device
according to a fourth embodiment of the present disclosure.
[0032] FIG. 19 illustrates a planar configuration of a first
transparent electrode with respect to photoelectric conversion
units, according to the fourth embodiment of the present
disclosure.
[0033] FIG. 20 is a schematic plan view illustrating the
configuration of a modified example of first and second transparent
electrodes of a dimming control laminated film according to the
fourth embodiment of the present disclosure.
[0034] FIG. 21 is a schematic cross-sectional view illustrating the
configuration of a main portion of a solid-state imaging device
according to a fifth embodiment of the present disclosure.
[0035] FIG. 22 is a diagram illustrating the relation between first
transparent electrodes of the solid-state imaging device according
to the fifth embodiment of the present disclosure and an
accumulated charge detecting circuit connected thereto.
[0036] FIG. 23 is a diagram illustrating the relation between a
first transparent electrode of a solid-state imaging device
according to a modified example and an accumulated charge detecting
circuit connected thereto.
[0037] FIG. 24 is a configuration diagram in a case where the first
transparent electrodes are formed irregularly with respect to a
pixel area.
[0038] FIG. 25 is a schematic cross-sectional view illustrating the
configuration of a main portion of a solid-state imaging device
according to a sixth embodiment of the present disclosure.
[0039] FIG. 26 is a diagram illustrating the relation between a
first transparent electrode of the solid-state imaging device
according to the sixth embodiment of the present disclosure and an
accumulated charge detecting circuit connected thereto.
[0040] FIG. 27 is a schematic cross-sectional view illustrating the
configuration of a main portion of a solid-state imaging device
according to a seventh embodiment of the present disclosure.
[0041] FIG. 28 is a schematic cross-sectional view illustrating the
configuration of a main portion of a solid-state imaging device
according to an eighth embodiment of the present disclosure.
[0042] FIG. 29 is a schematic configuration diagram of an
electronic apparatus according to a ninth embodiment of the present
disclosure.
[0043] FIG. 30 is a schematic configuration diagram of an
electronic apparatus according to a tenth embodiment of the present
disclosure.
[0044] FIG. 31 is a schematic configuration diagram of an
electronic apparatus according to an eleventh embodiment of the
present disclosure.
DETAILED DESCRIPTION
[0045] Hereinafter, examples of a solid-state imaging device, a
manufacturing method thereof, and an electronic apparatus according
to embodiments of the present disclosure will be described with
reference to FIGS. 1 to 31. Embodiments of the present disclosure
will be described in the following order. However, the present
disclosure is not limited to the examples described below.
[0046] 1. First Embodiment: Example of Solid-State Imaging Device
Formed By Bringing Transparent Electrode into Direct Contact with
Substrate
[0047] 2. Second Embodiment: Example in Which Dimming Control
Laminated Film Is Formed On Upper Portion of Solid-State Imaging
Device
[0048] 3. Third Embodiment: Example in Which Dimming Control
Laminated Film Formed From Electrochromic Layer Is Formed
Immediately above On-Chip Lens
[0049] 4. Fourth Embodiment: Example of Solid-State Imaging Device
in Which Dimming Control Laminated Film Formed From Electrochromic
Layer Is Formed To Be Common To All Pixels in Lower Layer of Color
Filter
[0050] 5. Fifth Embodiment: Example of Solid-State Imaging Device
in Which Dimming Control Laminated Film Formed From Electrochromic
Layer Is Formed For Each Pixel/Pixel Row in Lower Layer of Color
Filter
[0051] 6. Sixth Embodiment: Example of Solid-State Imaging Device
in Which Dimming Control Laminated Film Formed From Electrochromic
Layer Is Formed For Predetermined Pixel in Lower Layer of Color
Filter
[0052] 7. Seventh Embodiment: Example of Solid-State Imaging Device
in Which Dimming Control Laminated Film Formed From Liquid Crystal
Layer Is Formed In Lower Layer of Color Filter
[0053] 8. Eighth Embodiment: Example of Solid-State Imaging Device
in Which Photoelectric Conversion Layer Having Organic
Photoelectric Conversion Film Is Formed Immediately above On-Chip
Lens
[0054] 9. Ninth Embodiment: Electronic Apparatus Including
Solid-State Imaging Device in Which Dimming Control Laminated Film
Is Formed
[0055] 10. Tenth Embodiment: Electronic Apparatus Including
Aperture Diaphragm Formed From Dimming Control Laminated Film
[0056] 11. Eleventh Embodiment: Electronic Apparatus
[0057] Including Shutter Formed From Dimming Control Laminated
Film
1. First Embodiment
Solid-State Imaging Device
[0058] FIG. 1 illustrates the whole configuration of a solid-state
imaging device 1 according to a first embodiment of the present
disclosure. In this embodiment, a CCD-type solid-state imaging
device in which a transparent electrode is formed on the front face
of a substrate for reducing noise will be described as an
example.
[0059] As illustrated in FIG. 1, the solid-state imaging device 1
of this embodiment is configured to include a plurality of light
receiving units 2 formed on a substrate 6, a vertical transfer
register 3, a horizontal transfer register 4, and an output circuit
5. A unit pixel 7 is configured by one light receiving unit 2 and
the vertical transfer register 3 adjacent to the light receiving
unit 2. In addition, an area in which a plurality of pixels 7 are
formed is formed as a pixel area 8.
[0060] The light receiving unit 2 is configured by a photoelectric
conversion unit that is formed from a photodiode, and a plurality
of the light receiving units 2 are formed in a matrix pattern in
the horizontal direction and the vertical direction of the
substrate 6. In the light receiving unit 2, signal charge is
generated in accordance with incident light through photoelectric
conversion and is accumulated.
[0061] The vertical transfer register 3 is formed to have a CCD
structure, and a plurality of the vertical transfer registers 3 are
formed in the vertical direction for each light receiving unit 2
arranged in the vertical direction. This vertical transfer register
3 reads out signal charge accumulated in the light receiving unit 2
and transfers the signal charge in the vertical direction. A
transfer stage on which the vertical transfer register 3 of this
exemplary embodiment is formed, for example, is configured to be
driven with four phases in accordance with a transfer pulse that is
applied by a transfer driving pulse circuit that is not illustrated
in the figure. In addition, a final stage of the vertical transfer
register 3 is configured to transfer signal charge maintained on
the final stage to the horizontal transfer register 4 in accordance
with the application of the transfer pulse.
[0062] The horizontal transfer register 4 is formed to have a CCD
structure and is formed at one end of the final stage of the
vertical transfer register 3. The transfer stage on which the
horizontal transfer register 4 is formed transfers the signal
charge that is vertically transferred by the vertical transfer
register 3 in the horizontal direction for each horizontal
line.
[0063] The output circuit 5 is formed at the final stage of the
horizontal transfer register 4. The output circuit 5 performs
electric charge-to-voltage conversion of the signal charge that is
horizontally transferred by the horizontal transfer register 4 and
outputs a resultant signal as a video signal.
[0064] According to the solid-state imaging device 1 having the
above-described configuration, the signal charge that is generated
and accumulated by the light receiving unit 2 is transferred in the
vertical direction by the vertical transfer register 3 and is
transferred to the inside of the horizontal transfer register 4.
Then, the signal charge transferred to the inside of the horizontal
transfer register 4 is transferred in the horizontal direction and
is output as a video signal through the output circuit 5.
[0065] Next, the cross-sectional configuration of the pixel area 8
of the solid-state imaging device 1 according to this exemplary
embodiment will be described. FIG. 2 is a schematic cross-sectional
view illustrating the configuration of pixels 7, which are adjacent
to each other in the horizontal direction, of the solid-state
imaging device 1 according to this exemplary embodiment.
[0066] As illustrated in FIG. 2, the solid-state imaging device 1
according to this exemplary embodiment includes a substrate 11, a
wiring layer 58, a color filter layer 18, and an on-chip lens
19.
[0067] The substrate 11 is configured by a semiconductor substrate
that is formed from silicon and, for example, is configured by a
p-type semiconductor layer. In a desired area located on the light
incident side of the substrate 11, a photoelectric conversion unit
PD that is formed from a photodiode is formed. In the photoelectric
conversion unit PD, a main photodiode is configured by a p-n
junction of a p-type semiconductor area 51 of high density that is
formed on the front face side of the substrate 11 and an n-type
semiconductor area 56 that is formed at the lower portion thereof.
In the photoelectric conversion unit PD, photoelectric conversion
of incident light is performed, whereby signal charge is generated
and accumulated.
[0068] In addition, in an area adjacent to the photoelectric
conversion unit PD, a transfer channel unit 55 is formed which
configures the vertical transfer register 3 having the CCD
structure illustrated in FIG. 1. The transfer channel unit 55 is
configured by an n-type semiconductor area that is formed so as to
extend in the vertical direction, and one transfer channel unit 55
is formed for each column. Furthermore, in a lower portion of the
n-type semiconductor area that configures the transfer channel unit
55, a p-well layer 54 is formed which is configured by a p-type
semiconductor area. In addition, an area between the transfer
channel unit 55 and the photoelectric conversion unit PD is
configured as a read-out channel unit 57, and the signal charge
generated and accumulated by the photoelectric conversion unit PD
is read out by the transfer channel unit 55 through the read-out
channel unit 57 and is transferred through the inside of the
transfer channel unit 55. Furthermore, in an area surrounding one
photoelectric conversion unit PD and the transfer channel unit 55
that is adjacent to the photoelectric conversion unit PD, an
element isolating area 53 that is configured by a high-density
p-type semiconductor area is formed. An area that is surrounded by
the element isolating area 53 configures one pixel.
[0069] The wiring layer 58 is configured by a transfer electrode
13, a transparent electrode 14, an insulating film 15, a light
shielding film 16, and an interlayer insulating film 17. The
transfer electrode 13 is formed in an upper portion of the transfer
channel unit 55 and the read-out channel unit of the substrate 11
through the gate insulating film 12, and a plurality of the
transfer electrodes 13 are formed so as to be isolated in the
vertical direction along the transfer channel unit 55.
[0070] The transparent electrode 14 is composed of graphene and is
formed on the whole face of the substrate 11 that is located on the
light incident side so as to cover the substrate surface located on
the light incident side on the photoelectric conversion unit PD in
which the transfer electrode 13 is not formed and cover the
transfer electrode 13 through the insulating film 15. The
transparent electrode 14 is provided with the ground electric
potential through a wiring that is not illustrated in the figure. A
detailed configuration of the transparent electrode 14 will be
described later.
[0071] The light shielding film 16 is formed so as to cover the
transfer electrode 13 through the interlayer insulating film 17
that is formed on the whole face of the upper portion of the
transparent electrode 14, and an end portion located on a side that
is brought into contact with the photoelectric conversion unit PD
is formed so as to partially hang over the upper portion of the
photoelectric conversion unit PD. The light shielding film 16 is
formed by using a material that can shield light and, for example,
is formed by using Al, W, or the like.
[0072] In the wiring layer 58, the interlayer insulating film 17
that covers the transfer electrode 13 and the transparent electrode
14 and flattens the surface is included. In FIG. 2, although only
the transfer electrode 13, the transparent electrode 14, and the
light shielding film 16 are illustrated in the wiring layer 58,
desired films such as a wiring film that is used for supplying a
driving pulse to the transfer electrode 13 and a metal light
shielding film are additionally formed in the wiring layer 58.
[0073] The color filter layer 18 is formed on an upper portion of
the wiring layer 58 that is flattened, and the color filter layers
18 of R (red), G (green), and B (blue) are formed for each pixel
and, for example, is arranged so as to be a Bayer array.
Alternatively, as the color filter layer 18, a color filter layer
that transmits the same color for all the pixels 7 may be used. The
combination of colors in the color filter layer can be variously
selected in accordance with the specification.
[0074] The on-chip lens 19 is formed on an upper portion of the
color filter layer 18, and the front face thereof is in a convex
shape for each pixel 7. Incident light is collected by the one-chip
lens 19 and incident on the photoelectric conversion unit PD of
each pixel 7 with high efficiency.
[0075] As above, in the solid-state imaging device 1 according to
this exemplary embodiment, the incident light is collected so as to
be incident on the photoelectric conversion unit PD of the
substrate 11 by the on-chip lens 19. Then, in the photoelectric
conversion unit PD, signal charge corresponding to the light amount
of the incident light is generated and accumulated, and the
accumulated signal charge is transferred in the vertical direction
through the transfer channel unit 55. Thereafter, the signal charge
is horizontally transferred in the horizontal transfer register 4
and then output as a video signal.
[0076] In the solid-state imaging device 1 according to this
exemplary embodiment, the transparent electrode 14 is formed so as
to be directly brought into contact with the front face of the
substrate 11 that is located on the upper part of the photoelectric
conversion unit PD and is configured to be supplied with the ground
electric potential. Accordingly, since the transparent electrode 14
acts as the drain of holes, holes (positive holes) accumulated in
the p-type semiconductor area of each photoelectric conversion unit
PD are swept out through the transparent electrode 14. Therefore,
the signal charge amount (Qs) in each photoelectric conversion unit
PD is at the same level as that of the photoelectric conversion
units PD located on the upper and lower sides in the vertical
direction, whereby the unevenness of the signal charge amount (Qs)
can be decreased.
[0077] In a solid-state imaging device 1 in the related art in
which the transparent electrode 14 is not formed, a depletion area
can be widened on the boundary of the p-type semiconductor area
that configures the photoelectric conversion unit PD due to
impurity ions that are present within a phosphorous gate glass film
configuring the interlayer insulating film 17 located on the upper
portion of the light shielding film 16. As a result, there is a
concern that a dark current may increase. On the other hand,
according to this exemplary embodiment, by disposing the
transparent electrode 14 so as to be directly brought into contact
with the substrate located on the upper portion of the
photoelectric conversion unit PD, the depletion of the boundary is
prevented, whereby the dark current can be decreased.
[0078] Next, the configuration of the transparent electrode 14 that
is used in this exemplary embodiment will be described in
detail.
[0079] FIG. 3 shows a plan view illustrating the configuration of
the transparent electrode 14 that is used in this exemplary
embodiment. As illustrated in FIG. 3, in this exemplary embodiment,
the transparent electrode 14 has a first area (hereinafter,
referred to as an electrode portion 31) that is formed from
graphene and a second area that is formed from a plurality of air
gaps (hereinafter, referred to as openings 20) and is configured in
the shape of a film (sheet shape). The graphene that is used for
the transparent electrode 14 in this exemplary embodiment is a
material formed from polyaromatic molecules formed by combining a
plurality of carbon atoms and is in the shape of a film. This
film-shape graphene is formed by covalently bonding carbon atoms
and is understood to be configured as a single layer, and the
thickness of one layer is about 0.3 nm.
[0080] As the material characteristics of grapheme that configures
the transparent electrode 14, the transmittance in a case where
there is no opening 20 is 97.7.OMEGA., the thickness of the layer
is 0.3 nm in the case of a single layer, and the resistance value
is about 100.OMEGA.. By stacking the film-shaped graphene, which is
configured as a single layer, to be a plurality of layers, the
transmittance and the resistance value can be changed. Accordingly,
by changing the number of stacked layers of graphene, the
transmittance and the resistance value of the transparent electrode
14 can be appropriately adjusted based on the characteristics
demanded to the device.
[0081] For example, by stacking the film-shaped graphene, the
transmittance decreases by 2.3% for every layer. In addition, the
resistance value of the graphene in the case of two layers is 1/2
of the resistance value in the case of one layer, and the
resistance value in the case of three layers of the graphene is 1/3
of the resistance value in the case of one layer. Furthermore, by
forming an opening 20 in the graphene that configures the
transparent electrode 14, the transmittance can be increased to be
higher than 97.7% that is the transmittance of the material.
[0082] As illustrated in FIG. 3, the transparent electrode 14 used
in this exemplary embodiment is configured to include a plurality
of openings 20. When an average diameter (hereinafter, referred to
as an opening diameter) of the openings 20 is denoted by "a", an
average dimension (hereinafter, referred to as an electrode width)
between openings adjacent to each other is denoted by "b", changes
in transmittance in a case where the opening diameter a is fixed,
and the electrode width b is changed is illustrated in FIG. 4. In
FIG. 4, the horizontal axis is the electrode width b, and the
vertical axis is the transmittance.
[0083] As illustrated in FIG. 4, it can be understood that the
transmittance of graphene increases in accordance with an increase
in the opening diameter a and a decrease in the electrode width b
and continuously changes in accordance with the dimensions of the
opening diameter a and the electrode width b. Accordingly, by
determining target transmittance (hereinafter, referred to as
target transmittance Tm), the dimensions of the opening diameter a
and the electrode width b can be set. Hereinafter, a method of
setting the dimensions of the opening diameter a and the electrode
width b using an equation will be illustrated.
[0084] First, the target transmittance Tm can be acquired by using
Equation (1) using the transmittance of a case where the opening 20
is not formed in the graphene, that is, the transmittance
(hereinafter, referred to as normal transmittance Ti=2.3%) in a
case where the coverage factor according to the graphene is 100%
and the aperture ration A (%).
Tm=100-Ti.times.A (1)
[0085] At this time, the aperture ration ratio A (%) can be
represented by Equation (2) using the opening diameter a and the
electrode width b.
A={(a+b).sup.2-a.sup.2}/(a+b).sup.2 (2)
[0086] Accordingly, by determining the target transmittance Tm, the
aperture ratio A (%) can be acquired by using Equation (1), and, by
determining one of the opening diameter a and the electrode width b
by substituting the aperture ratio A (%) in Equation (2), the value
of the other can be calculated. Then, by forming the opening in the
graphene by applying the opening diameter a and the electrode width
b, the transparent electrode 14 having the target transmittance Tm
can be formed.
[0087] For example, in a case where the target transmittance Tm is
98%, the aperture ratio A(%) is 86.95% (derived by 98=100-2.3 A) by
using Equation (1). When the opening diameter a is determined as 50
nm, by using Equation (2) with the electrode width as x, x (that is
the electrode width b) is approximately 100 by using
86.95={(50+b).sup.2-a.sup.2}/(a+b).sup.2. In other words, the
electrode width b is demanded to be 100 nm.
[0088] However, in order to allow the transparent electrode 14
formed from graphene to have conductivity, it is preferable that
the width of the narrowest portion of the electrode portion 31 is
larger than 10 nm. Accordingly, in this embodiment, it is
preferable that the opening 20 of the transparent electrode 14 is
set in the range in which the narrowest portion of the electrode
width b is equal to or larger than 10 nm.
[0089] In addition, the resistance of the transparent electrode 14
changes in accordance with the opening diameter a and the electrode
width b formed in the transparent electrode 14. FIG. 5 is a diagram
illustrating a change in the resistance of the transparent
electrode in a case where the opening diameter a is fixed, and the
electrode width b is changed. As illustrated in FIG. 5, it is
understood that the larger the opening diameter a is, the higher
the resistance is, and the larger the electrode width b is, the
lower the resistance is. In this embodiment, the resistance of the
transparent electrode 14 can be also changed by the shape of the
opening 20 instead of stacking the transparent electrode 14.
[0090] Next, the result of measurement of the transmittance (%) and
the resistance (.OMEGA.) with respect to the aperture ratio of the
transparent electrode 14 will be described. FIG. 6 schematically
illustrates the configuration of the transparent electrode 14 that
is used when the transmittance and the resistance with respect to
the aperture ratio are actually measured. In this experiment, as
illustrated in FIG. 6, the transparent electrode 14 was used in
which regular hexagon-shaped openings 20 are formed. In the
evaluation presented below, the aperture ratio is changed in the
range of 0 to 87.5% by fixing the electrode width b illustrated in
FIGS. 6 to 8 .mu.m and changing the opening diameter a, and the
transmittance and the resistance were measured respectively.
[0091] FIGS. 7 and 8 illustrate the results of measurements of the
transmittance when the aperture ratio of the transparent electrode
14 illustrated in FIG. 6 is changed in the range of 0 to 87.5%. In
FIG. 7, the transmittance at a time when the wavelength is changed
in the range of 300 nm to 1500 nm is illustrated, the horizontal
axis is the wavelength (nm), and the vertical axis is the
transmittance (%). On the other hand, in FIG. 8, the transmittance
with respect to the aperture ratio at a time when the wavelength is
fixed to 550 nm is illustrated, the horizontal axis is the aperture
ratio (%), and the vertical axis is the transmittance (%).
[0092] As illustrated in FIG. 7, it can be understood that, in the
entire measured wavelength region, the transmittance increases in
accordance with an increase in the aperture ratio. While the
transmittance for the visible region (for example, the
wavelength=550 nm) is 96.3% in a case where the aperture ratio is
0%, it can be understood that the transmittance of 99% or more can
be achieved by setting the aperture ratio to 87.5%. In addition, as
is apparent from FIG. 8, it can be understood that the
transmittance increases in proportion to the aperture ratio in a
case where the wavelength is set to be constant.
[0093] In a case where the solid-state imaging device is applied to
an electronic apparatus such as a mobile apparatus or a camcorder
that images a moving subject, it is demanded that a transparent
electrode having higher transmittance be applied to the solid-state
imaging device. Accordingly, it is ideal that the transmittance of
the transparent electrode 14 used in the solid-state imaging device
1 according to this exemplary embodiment under lightness is close
to 100%, and it is preferable that at least the transmittance of
99% or more can be realized. Accordingly, it is preferable that the
aperture ratio of the transparent electrode 14 used in the
solid-state imaging device 1 according to this embodiment is equal
to or higher than 87.5%.
[0094] In the solid-state imaging device 1 according to this
embodiment, by using the transparent electrode 14 that can realize
transmittance of 99% or higher, the solid-state imaging device 1
can be applied to a specific-purpose dedicated apparatus such as a
monitoring camera or a medical imaging apparatus in addition to a
general-consumer electronic apparatus such as a mobile apparatus or
a camcorder. In addition, not only a still image but also a moving
subject image can be photographed by using such an electronic
apparatus.
[0095] Next, FIG. 9 illustrates the resistance (the value of an
actual measurement) at a time when the aperture ratio of the
transparent electrode 14 illustrated in FIG. 6 is changed in the
range of 0 to 87.5% and the resistance R (theoretical value) of the
transparent electrode having an opening that is calculated by using
Equation (3).
R={(2a+b).times.R.sub.0}/{(a+b).times.(1-p)} (3)
[0096] Here, a denotes an opening diameter, b denotes an electrode
width, p denotes an aperture ratio of an electrode that is formed
from graphene, and R.sub.0 is a resistance value of the transparent
electrode that is formed from graphene in a case where any opening
is not arranged.
[0097] As illustrated in FIG. 9, the resistance of the transparent
electrode 14 tends to be larger as the aperture ratio is increased.
In addition, although the actually measured value is a resistance
value lower than the theoretical value calculated by using Equation
(3), the tendency of the actual value was similar to that of the
theoretical value.
[0098] Next, FIG. 10 is a diagram illustrating the resistance (the
value of an actual measurement) in a case where AuCl.sub.3 is added
to the transparent electrode 14 and a surface modification is made
for the transparent electrode 14 and the resistance (theoretical
value) of the transparent electrode in a case where the addition of
AuCl.sub.3 is considered. In the evaluation illustrated in FIG. 10,
a transparent electrode to which AuCl.sub.3 is added is generated
by performing spin-coat of a nitromethane solution containing 5
mmol concentration of AuCl.sub.3 for the transparent electrode
having a desired aperture ratio, and the resistance value thereof
was measured. FIG. 10 illustrates an actual measurement value of
the resistance and a theoretical value acquired by using Equation
(3) for the aperture ratio illustrated in FIG. 9 with being
combined together. In FIG. 10, the horizontal axis is the
transmittance, and the vertical axis is the resistance value.
[0099] As illustrated in FIG. 10, it can be understood that the
resistance of the transparent electrode 14 can be decreased by
adding AuCl.sub.3. Accordingly, by adding AuCl.sub.3, the
transparent electrode 14 having high transmittance and a low
resistance value can be acquired, whereby it is possible to acquire
a solid-state imaging device of which the transmittance and the
resistance value are adjusted in accordance with the specifications
of an electronic apparatus. In the evaluation illustrated in FIG.
10, although AuCl.sub.3 is added, any material that decreases the
resistance value of the transparent electrode 14 may be used, and
HAuCl.sub.4, HNO.sub.3, HCl, or the like other than AuCl.sub.3 may
be used.
[0100] The transparent electrode 14 formed from graphene can be
formed by using a general manufacturing method and, for example,
can be formed by using the following method. First, a film that
contains a graphite catalyst is formed as a film on a substrate
formed from silicon or the like. Thereafter, a gas-phase carbon
supplying source is supplied to the film of the graphite catalyst,
and the gas-phase carbon supplying source is thermally processed so
as to generate graphene. Then, by cooling the graphene at
predetermined cooling speed, the film-shaped graphite is formed on
the upper portion of the graphite catalyst.
[0101] As the graphite catalyst, at least one metal selected from
among Ni, Co, Fe, Pt, Au, Al, Cr, Cu, Mg, Mn, Mo, Rh, Si, Ta, Ti,
W, U, V, and Zr or a combination thereof may be used. In addition,
as the gas-phase carbon supplying source, for example, at least one
selected from among carbon dioxide, methane, ethane, ethylene,
ethanol, acetylene, propane, butane, butadiene, pentane, pentene,
cyclopentadien, hexane, cyclohexane, benzene, and toluene may be
used.
[0102] By separating the film-shaped graphite formed as above from
the graphite catalyst film, the graphite can be used as the
transparent electrode 14. The transparent electrode 14 according to
this exemplary embodiment has an opening 20. This opening 20 can be
formed by performing an etching process for the graphite formed in
the shape of a film. FIGS. 11A to 11D show process diagrams
illustrating a method of forming the transparent electrode 14 that
has the opening 20.
[0103] First, as illustrated in FIG. 11A, for example, on the upper
portion of a substrate 400 formed from silicon, a graphene film 14a
generated as described above is formed, and a resist layer 401
located on the upper portion thereof is formed through spin coat.
Next, as illustrated in FIG. 11B, the opening 401a is formed in the
resist layer 401 by using a general photolithographic method.
[0104] Next, as illustrated in FIG. 11C, the graphene film 14a is
etched by using an RIE (Reactive Ion Etching) method using the
resist layer 401 having the opening 401a as a mask. Thereafter, as
illustrated in FIG. 11D, by removing the resist layer 401, a
transparent electrode 14 having the opening 20 is formed.
[0105] Then, in this exemplary embodiment, the transparent
electrode 14, which has the opening 20 that has been completed,
formed from film-shaped graphite is stacked on the light incident
side of the substrate 11 on which the photoelectric conversion unit
PD is formed. Here, although the film-shaped transparent electrode
14 having the opening 20 is stacked on the upper portion of the
substrate 11, it may be configured such that the transparent
electrode 14 that is not open is formed on the upper portion of the
substrate 11, and, thereafter, the opening 20 is formed.
[0106] However, in a case where the opening diameter a of the
opening 20 formed in the transparent electrode 14 is large with
respect to the pixel size, the opening 20 is recognized as a shape,
and there is a problem in that the visibility is degraded. In a
case where the opening diameter a of the opening 20 formed in the
transparent electrode 14 is less than 10% of the pixel size, there
is a little effect on the visibility, and accordingly, it is
preferable that the opening diameter of the opening 20 formed in
the transparent electrode 14 is less than 10% of the pixel size.
For example, in a case where the pixel size 1 .mu.m, for example,
the opening diameter a of the opening 20 formed in the transparent
electrode 14 is set to 50 nm, whereby the effect on the visibility
can be decreased.
[0107] Meanwhile, the formation of the opening 20 in the
transparent electrode 14 is formed through etching as described
above, and accordingly, the thinning of the electrode width b is
hardly limited by the manufacturing process. Accordingly, the
thinning of the electrode width b can be performed. Therefore, in
this embodiment, it is preferable to increase the aperture ratio of
the transparent electrode 14 by appropriately changing the
electrode width b in a state in which the opening diameter a of the
opening 20 of the transparent electrode 14 is maintained in the
range that is 1% or more and 10% or less of the pixel size.
Accordingly, the transparent electrode 14 that has transmittance of
99% or more and does not have any effect on the visibility can be
acquired.
[0108] In the related art, generally, ITO is used as the material
of the transparent electrode 14. The transmittance of ITO is 90%,
and, in a case where the transparent electrode 14 formed from ITO
is formed on the upper portion of the photoelectric conversion unit
PD as in JP-A-07-94699, there is loss of 10% of the transmittance.
In addition, since the film thickness of the ITO film is large, the
optical path changes, and there is a concern that the optical
characteristics are affected. On the other hand, like this
exemplary embodiment, by using graphene having the opening 20 as
the transparent electrode 14, the transmittance can be set to be
higher than 97.7%. In addition, since one layer of the film-shaped
graphene is as thin as 0.3 nm, the optical path is not affected.
Accordingly, an advantage of suppressing a dark current and the
shading and the improvement of the optical characteristics can be
realized altogether.
[0109] As above, by configuring the transparent electrode 14 by
using graphene having the opening 20, the transparent electrode 14
can attain the role of the electrode without affecting the optical
characteristics. The example in which the transparent electrode 14
is used in the solid-state imaging device 1 according to this
exemplary embodiment is merely an example, and the position of the
transparent electrode 14 is set in accordance with the structure of
the device. Accordingly, in a solid-state imaging device in the
related art, by replacing ITO used for the transparent electrode
with graphene having a desired opening, the advantages similar to
those of this exemplary embodiment can be acquired, and
accordingly, the transmittance is improved, whereby the applicable
application can be widened.
[0110] In addition, in the case illustrated in FIG. 3, although the
shape of the opening 20 formed in the transparent electrode 14 is
an oval shape, the shape of the opening is not limited to the oval
shape and may be changed to various shapes such as a circular
shape, a semicircular shape, a polygonal shape, and the like.
Furthermore, in this exemplary embodiment, although an example has
been described in which one layer of the transparent electrode 14
is formed, a plurality of layers of transparent electrodes may be
formed so as to be stacked.
[0111] In addition, in this exemplary embodiment, although an
example has been described in which graphene is used as the
material of the transparent electrode 14, the present disclosure is
not limited to graphene, and, for example, carbon nanotubes as the
same nano carbon material may be used. In a case where target
transmittance can be acquired by arranging the opening in a
transparent electrode that is formed from carbon nanotubes formed
in the shape of a film, the advantages similar to those of the
solid-state imaging device 1 according to this exemplary embodiment
can be acquired.
2. Second Embodiment
Solid-State Imaging Device
[0112] Next, a solid-state imaging device according to a second
embodiment of the present disclosure will be described. FIG. 12 is
a schematic cross-sectional view illustrating the configuration of
a solid-state imaging device 21 according to this exemplary
embodiment. The solid-state imaging device 21 according to this
exemplary embodiment is an example in which a dimming control
laminated film 27 is disposed on the light incident side of the
solid-state imaging device main body 29 that is mounted inside a
resin package 38.
[0113] The solid-state imaging device 21 according to this
exemplary embodiment includes the solid-state imaging device main
body 29 that is configured by including a plurality of
photoelectric conversion units on a substrate, the resin package 38
that seals the solid-state imaging device main body 29, sealing
glasses 28a and 28b, and the dimming control laminated film 27.
[0114] The resin package 38 is composed of an electrically
insulating material and is configured as a casing having a shallow
bottom in which a bottom portion is included on one side, and the
other side is open. On the bottom face of the resin package 38, the
solid-state imaging device main body 29 is disposed, and, on the
opening end side thereof, the sealing glasses 28a and 28b and the
dimming control laminated film 27 are formed.
[0115] FIG. 13 shows a schematic cross-sectional view illustrating
the configuration of the solid-state imaging device main body 29 in
an enlarged scale. As illustrated in FIG. 13, the solid-state
imaging device main body 29 is configured to include a substrate 30
in which a plurality of photoelectric conversion units PD are
formed, a wiring layer 36, a color filter layer 34, and an on-chip
lens 35.
[0116] The substrate 30 is configured by a semiconductor substrate
and, on the light incident side in the pixel area, a photoelectric
conversion unit PD that is formed from a photodiode is formed for
each pixel.
[0117] The wiring layer 36 is configured to include a plurality of
(two layers in FIG. 13) layers of wirings 32 that are stacked with
an interlayer insulating film 33 interposed therebetween and is
formed so as to open the upper portion of the photoelectric
conversion unit PD.
[0118] The color filter layer 34 is formed on an upper portion of
the wiring layer 36 that is flattened, and the color filter layers
34 of R (red), G (green), and B (blue) are formed for each pixel,
for example, so as to form a Bayer array. Alternatively, as the
color filter layer 34, a color filter layer 34 that transmits the
same color for all the pixels may be used. The combination of
colors in the color filter layer can be variously selected in
accordance with the specification.
[0119] The on-chip lens 35 is formed on an upper portion of the
color filter layer 34 and is formed in a convex shape for each
pixel. Incident light is collected by the one-chip lens 35 and
incident on the photoelectric conversion unit PD of each pixel with
high efficiency.
[0120] In the solid-state imaging device main body 29 having such a
configuration, a connection wiring, which is not illustrated in the
figure, is connected to the inside of the resin package 38 and is
configured to be electrically connected to the outside of the resin
package 38 through the connection wiring.
[0121] The sealing glasses 28a and 28b are configured by
transparent members and are formed so as to maintain the inside of
the resin package 38 to be air-tight by sealing the opening portion
of the resin package 38. In addition, in an area interposed between
two sealing glasses 28a and 28b, the dimming control laminated film
27 is formed.
[0122] The dimming control laminated film 27 is configured by a
laminated film that is formed from a dimming control layer 24, a
solid electrolyte layer 25, and an ion storing layer 26 and first
and second transparent electrodes 22 and 23 that hold them
therebetween and is formed on the entire upper face of the
solid-state imaging device main body 29. At this time, the
direction of stacking the first transparent electrode 22, the
dimming control layer 24, the solid electrolyte layer 25, the ion
storing layer 26, and the second transparent electrode 23 is
configured to be the incidence direction of light L.
[0123] As the material of the dimming control layer 24, a magnesium
compound such as Mg--Ni can be used.
[0124] As the material of the solid electrolyte layer 25, a
Ta-system oxide can be used.
[0125] The ion storing layer 26 is a dimming control reacting
material layer and is configured by using a so-called
electrochromic material. As the material of the ion storing layer
26, representatively, a tungsten oxide can be used.
[0126] The first and second transparent electrodes 22 and 23 used
in this exemplary embodiment are configured by using film-shaped
graphene having a plurality of openings and have a configuration
that is similar to that of the transparent electrode 14 according
to the first embodiment illustrated in FIG. 3. In addition, the
openings formed in the first and second transparent electrodes 22
and 23 according to this exemplary embodiment are formed so as to
have an opening diameter a of about 100 nm and an electrode width
of about 50 nm, and accordingly, the opening diameter a is formed
to be sufficiently smaller than the pixel area. Accordingly, there
is a little influence on the photoelectric conversion rate and the
mobility of electrons, the contact resistance, and the like.
[0127] In this exemplary embodiment, the dimming control laminated
film 27 is formed by bringing the first and second transparent
electrodes 22 and 23 formed from graphene formed in the shape of a
film in advance into tight contact with both sides of the laminated
film that is formed from the dimming control layer 24, the solid
electrolyte layer 25, and the ion storing layer 26. Then, the
dimming control laminated film 27 is arranged on the upper portion
of the sealing glass 28a located in the lower layer, and the
sealing glass 28b is arranged from the upper portion thereof,
whereby the solid-state imaging device 21 according to this
exemplary embodiment can be acquired.
[0128] In addition, the dimming control laminated film 27, as
illustrated in FIG. 12, is configured such that a desired voltage V
can be applied between the first and second transparent electrodes
22 and 23. Although FIG. 12 schematically illustrates the
connection of the voltage V, actually, it is configured such that
the voltage V is applied from a wiring, which is not illustrated in
the figure, formed inside the resin package 38. In the dimming
control laminated film 27, by applying the voltage V between the
first and second transparent electrodes 22 and 23, the ion storing
layer 26 is colored in accordance with the applied voltage, whereby
the transmittance of the dimming control laminated film 27
changes.
[0129] FIGS. 14A and 14B illustrate a change in the transmittance
of the dimming control laminated film 27 with respect to the
applied voltage V. As illustrated in FIG. 14A, when a voltage is
applied at specific time, the transmittance of the dimming control
laminated film 27 that has been approximately 0% instantaneously
rises to a level less than 50%, and, thereafter, when an reverse
voltage is applied at specific time, the transmittance that has
been maintained at a level less than 50% becomes approximately 0%
again. As above, in the ion storing layer 26, the speed of a change
in transmittance with respect to a voltage is high, and after the
change, the changed transmittance is maintained. In addition, as
illustrated in FIG. 14B, the change in transmittance with respect
to the voltage may be configured to be opposite to that illustrated
in FIG. 14A depending on the specifications. A difference between
the cases illustrated in FIGS. 14A and 14B can be changed in
accordance with a method of configuring the material, and whether
the transmittance rises or drops by applying a desired voltage can
be determined based on the material.
[0130] According to the solid-state imaging device 21 of this
exemplary embodiment, by applying the desired voltage V between the
first and second transparent electrodes 22 and 23, the
transmittance of the dimming control laminated film 27 can be
changed. Accordingly, by lowering the transmittance in a case where
incident light is strong, overexposure can be prevented. In
addition, according to the solid-state imaging device 21 of this
exemplary embodiment, by changing the transmittance of the dimming
control laminated film 27, the dynamic range can be increased. FIG.
15 is a diagram illustrating signal characteristics of an output
signal 1 in the case of high sensitivity and an output signal 2 in
the case of low sensitivity. In FIG. 15, the horizontal axis is the
illumination, and the vertical axis is the saturated signal amount
of the solid-state imaging device main body.
[0131] A line denoted by "Signal 1" illustrated in FIG. 15 is a
saturation characteristic in a case where the dimming control
laminated film 27 is set as high transmission, and a line denoted
by "Signal 2" is a saturation characteristic in a case where the
transmittance is lowered by changing the voltage V applied to the
dimming control laminated film 27 from the case where Signal 1 is
acquired. A signal that is used as a video output is acquired by
subtracting noise from the saturated signal amount.
[0132] In a case where the transmittance of the dimming control
laminated film 27 is high, the saturated charge amount is
immediately reached due to high sensitivity, and a signal amount
acquired in a range represented by D1 illustrated in FIG. 15 is
output. On the other hand, in a case where the transmittance of the
dimming control laminated film 27 is low, a signal amount acquired
in a range represented by D2 (<D1) illustrated in FIG. 15 is
output due to low sensitivity. In other words, by setting the low
sensitivity, light of brightness in a range broader than that of
the case of the high sensitivity can be acquired. Accordingly, by
changing the voltage applied to the dimming control laminated film
27 in correspondence with a photographing scene, a dynamic range
corresponding to the photographing scene can be acquired.
[0133] As above, according to the solid-state imaging device of
this exemplary embodiment, by decreasing the transmittance by using
the dimming control laminated film 27, signal charge having broad
brightness can be acquired, and the dynamic range can be
increased.
[0134] The dynamic range is defined as the ratio of a saturated
signal amount, which is the maximum signal amount to noise. In a
case where white light to sunlight can be photographed by general
solid-state imaging device 21 without lowering the resolution, the
photographable range, as illustrated in FIG. 16, is 10.sup.2 to
10.sup.4 lux (Lx). In contrast to this, as illustrated in FIG. 16,
in a case where 10.sup.2 to 10.sup.5 lux (Lx) can be photographed,
the dynamic range is magnified by 10 times. When this is
represented by magnification power Lb of the dynamic range, the
magnification power Lb=10 log 10 A/B (dB), and A/B=10, and
accordingly, the magnification power is 10 decibel (dB). Here, when
the improved part x of the magnification power of the dynamic range
is determined, the attained magnification power D of the dynamic
range can be represented by the following Equation (4).
D=(1+x)Lb(%) (4)
[0135] Regarding the dynamic range, the improved part of the
magnification power of the dynamic range=the improved part of the
transmittance of the dimming control laminated film. Accordingly,
when the improved part x up to the attained magnification power is
determined, the opening diameter a illustrated in FIG. 3 can be
determined. In other words, since the attained magnification
power=the target transmittance, the opening diameter a can be
acquired similarly to Equation (2). Accordingly, the openings 20
that are necessary for magnifying the dynamic range can be set for
the first and second transparent electrodes 22 and 23 in accordance
with the specifications demanded for each solid-state imaging
device. In this exemplary embodiment, by using the first and second
transparent electrodes 22 and 23 in which a plurality of the
openings 20 are formed so as to have an opening diameter a of 50 nm
and an electrode width b of 100 nm, an advantage of magnifying the
dynamic range can be acquired.
[0136] Meanwhile, there is an example in which the dimming control
laminated film is configured by using ITO as a transparent
electrode in the related art. However, in a case where ITO is used
for the transparent electrode, a 10% loss of transmittance occurs
for one layer. Thus, in a case where two layers of ITO are used on
both sides, a 20% loss of the transmittance occurs. The improvement
of the transmittance directly influences the improvement of the
sensitivity. Accordingly, for example, in the solid-state imaging
device, the loss of the transmittance results in a decrease in the
magnification of the dynamic range.
[0137] On the other hand, according to the solid-state imaging
device 21 of this exemplary embodiment, by using film-shaped
graphene as the first and second transparent electrodes 22 and 23
used in the dimming control laminated film 27, the dynamic range
can be magnified without decreasing the sensitivity. In addition,
various changes such as the sizes and the formation positions of
the openings 20 of the first and second transparent electrodes 22
and 23 can be changed in accordance with a characteristic desired
to be realized and restrictions.
[0138] In addition, according to this exemplary embodiment,
although both the first and second transparent electrodes 22 and 23
that form the dimming control laminated film 27 are configured by
using graphene as an example, a configuration may be employed as an
example in which at least one of them is configured by using a
film-shaped material formed from graphene. Even in such a case, the
transmittance can be higher than that of a dimming control
laminated film using a transparent electrode that is formed from an
ITO film as in the related art.
3. Third Embodiment
Solid-State Imaging Device
[0139] Next, a solid-state imaging device according to a third
embodiment of the present disclosure will be described. FIG. is a
schematic cross-sectional view illustrating the configuration of a
main portion of a solid-state imaging device 40 according to this
exemplary embodiment. Although the solid-state imaging device 40
illustrated in FIG. 17 corresponds to the solid-state imaging
device main body 29 illustrated in FIG. 12, it will be described as
the solid-state imaging device here (this applies similarly to the
following embodiments). The solid-state imaging device 40 of this
exemplary embodiment is an example in which a dimming control
laminated film 27 is provided immediately above an on-chip lens 35.
In FIG. 17, the same reference numeral is assigned to a portion
corresponding to FIG. 12, and duplicate description thereof will
not be repeated.
[0140] As illustrated in FIG. 17, in the solid-state imaging device
40 according to this exemplary embodiment, the dimming control
laminated film 27 is formed on the upper portion of the on-chip
lens 35 through a flattening film 37. The dimming control laminated
film 27 is configured by a laminated film that is formed from a
dimming control layer 24, a solid electrolyte layer 25, and an ion
storing layer 26 and first and second transparent electrodes 22 and
23 that hold them therebetween. At this time, the direction of
stacking the first transparent electrode 22, the dimming control
layer 24, the solid electrolyte layer 25, the ion storing layer 26,
and the second transparent electrode 23 is configured to be the
incidence direction of light. The configuration of the dimming
control laminated film 27 is similar to that of the dimming control
laminated film 27 according to the second embodiment, and a
material and a configuration similar to those thereof may be
used.
[0141] Also in this exemplary embodiment, by applying a desired
voltage V between the first and second transparent electrodes 22
and 23, the transmittance of the dimming control laminated film 27
can be changed. Accordingly, similarly to the second embodiment,
the dynamic range can be magnified. In addition, according to the
solid-state imaging device 40 of this exemplary embodiment, the
dimming control laminated film 27 is formed immediately above the
on-chip lens 35, and accordingly, the magnification power is lower
than that of the solid-state imaging device 21 according to the
second embodiment, whereby the device can be miniaturized.
[0142] In addition, the advantages similar to those of the first
and second embodiments can be acquired.
[0143] Furthermore, in the solid-state imaging device 40 of this
exemplary embodiment, it is necessary to form a difference in the
refractive indices of the on-chip lens 35 and the first transparent
electrode 22 that is formed on the upper portion thereof or to
arrange an air layer between the on-chip lens 35 and the first
transparent electrode 22. Although not illustrated in FIG. 17,
actually, the dimming control laminated film 27 is formed on the
upper portion of the flattening film 37 located on the upper
portion of the on-chip lens 35 through an air layer. In the
solid-state imaging device 40 of this exemplary embodiment, as
illustrated in FIG. 12, is arranged inside a resin package and is
sealed by sealing glasses.
4. Fourth Embodiment
Solid-State Imaging Device
[0144] Next, a solid-state imaging device according to a fourth
embodiment of the present disclosure will be described. FIG. 18 is
a schematic cross-sectional view illustrating the configuration of
a main portion of a solid-state imaging device 50 according to this
exemplary embodiment. The solid-state imaging device 50 of this
exemplary embodiment is an example in which a dimming control
laminated film 27 is formed in a lower layer of a color filter
layer 34. In FIG. 18, the same reference numeral is assigned to a
portion corresponding to FIG. 17, and duplicate description thereof
will not be repeated.
[0145] As illustrated in FIG. 18, in the solid-state imaging device
50 according to this exemplary embodiment, the dimming control
laminated film 27 is formed between a wiring layer 36 formed on the
light emission side of a substrate 30 and a color filter layer 34.
The dimming control laminated film 27 is configured by a laminated
film that is formed from a dimming control layer 24, a solid
electrolyte layer 25, and an ion storing layer 26 and first and
second transparent electrodes 22 and 23 that hold them
therebetween. At this time, the direction of stacking the first
transparent electrode 22, the dimming control layer 24, the solid
electrolyte layer 25, the ion storing layer 26, and the second
transparent electrode 23 is configured to be the incidence
direction of light. The configuration of the dimming control
laminated film 27 is similar to that of the dimming control
laminated film 27 according to the second embodiment, and a
material and a configuration similar to those thereof may be
used.
[0146] FIG. 19 illustrates a planar configuration of the first
transparent electrode 22 with respect to photoelectric conversion
units PD, according to this exemplary embodiment. As illustrated in
FIG. 19, the first transparent electrode 22 that configures the
dimming control laminated film 27 is formed on the entire face of
the pixel area so as to cover the photoelectric conversion units PD
located in the pixel area.
[0147] In the dimming control laminated film 27 of this exemplary
embodiment, the first transparent electrode 22 is connected to an
accumulated charge detecting circuit 41, which detects signal
charge generated and accumulated by the photoelectric conversion
unit PD, through an amplifier circuit 42. The signal charge that is
generated and accumulated by the photoelectric conversion unit PD
of each pixel is transferred to the accumulated charge detecting
circuit 41. In the accumulated charge detecting circuit 41, the
amount of the detected signal charge is converted into an electric
potential, and the electric potential is applied to the first
transparent electrode 22 through the amplifier circuit 42 via an
output wiring. In this exemplary embodiment, electric potentials
that are based on the amounts of signal charge transferred from the
photoelectric conversion units PD of all the pixels to the
accumulated charge detecting circuit 41 are configured to be output
from the accumulated charge detecting circuit 41 to the first
transparent electrode 22. In addition, between the amplifier
circuit 42 and the first transparent electrode 22, a voltage
maintaining capacitor C of which one terminal is grounded is
connected. Furthermore, the second transparent electrode 23 is
grounded.
[0148] According to such a configuration, in the solid-state
imaging device 50 of this exemplary embodiment, an electric
potential that is based on the amount of signal charge generated
and accumulated by the photoelectric conversion unit PD is supplied
to the first transparent electrode 22. Then, the transmittance of
the dimming control laminated film 27 is configured to be adjusted
in accordance with the supplied electric potential. For example, in
a case where strong light is incident, the transmittance of the
dimming control laminated film 27 is configured to decrease based
on the signal output. Accordingly, the magnification of the dynamic
range is achieved, and additionally advantages that are similar to
those of the first to third embodiments can be acquired.
[0149] In the solid-state imaging device 50 of this exemplary
embodiment, an example has been described in which the
configuration of the first and second transparent electrodes 22 and
23 is similar to that illustrated in FIG. 17. However, the size and
the formation position of the opening 20 may be variously changed.
FIG. 20 illustrates a planar configuration of a modified example of
the first and second transparent electrodes 22 and 23 of the
dimming control laminated film 27. In FIG. 20, the planar layout of
a pixel area 48 and the configuration of the first and second
transparent electrodes 22 and 23 corresponding thereto are
illustrated in parallel with each other. As illustrated in FIG. 20,
in the first and second transparent electrodes 22 and 23 according
to the modified example, opening portions 49 having different
opening diameters for each pixel are formed, and the electrode
widths are different for each pixel. In addition, any opening is
not formed in an optical black pixel area (OPB pixel area) that is
formed on the outer side of an effective pixel area.
[0150] As above, in the OPB pixel area that is commonly covered
with a light shielding film and is light-shielded so as to output a
black reference signal, it is not necessary to transmit light, and
accordingly, any opening may not be formed in the transparent
electrodes. As above, in the OPB pixel area, by not arranging any
opening in the first and second transparent electrodes 22 and 23,
the accuracy of the output of the black reference signal can be
improved.
5. Fifth Embodiment
Solid-State Imaging Device
[0151] Next, a solid-state imaging device according to a fifth
embodiment of the present disclosure will be described. FIG. 21 is
a schematic cross-sectional view illustrating the configuration of
a main portion of a solid-state imaging device 60 according to this
exemplary embodiment. The solid-state imaging device 60 of this
exemplary embodiment is an example in which the first transparent
electrode 22 is patterned so as to be able to change the
transmittance for each pixel in the solid-state imaging device 50
according to the fourth embodiment. In FIG. 21, the same reference
numeral is assigned to a portion corresponding to FIG. 18, and
duplicate description thereof will not be repeated.
[0152] As illustrated in FIG. 21, according to the solid-state
imaging device 60 of this exemplary embodiment, first transparent
electrodes 62 of a dimming control laminated film 67 that are
located on a side electrically connected to an accumulated charge
detecting circuit 41 connected to a photoelectric conversion unit
PD of each pixel are formed to be separated for each pixel. On the
other hand, a second transparent electrode 23 that is applied with
the ground electric potential is formed to be common to all the
pixels. The separated first transparent electrodes 62 of the
solid-state imaging device 60 can be formed by separating them
through patterning for each pixel. Between the first transparent
electrode 62 that is separatedly formed and the first transparent
electrode 62 adjacent thereto, an insulating film 68 is buried.
[0153] FIG. 22 is a diagram illustrating the relation between the
first transparent electrodes 62, which are formed in correspondence
with the photoelectric conversion unit PD of each pixel, of the
solid-state imaging device 60 according to this exemplary
embodiment and the accumulated charge detecting circuit 41
connected thereto. As illustrated in FIG. 22, the first transparent
electrode 62 is formed for each photoelectric conversion unit PD
arranged in R, G, and B, and each first transparent electrode 62 is
formed to have a size for completely covering the upper portion of
the corresponding photoelectric conversion unit PD. In addition,
the accumulated charge detecting circuit 41 that is connected to
each photoelectric conversion unit PD is connected to each first
transparent electrode 62 corresponding to each photoelectric
conversion unit PD.
[0154] According to this exemplary embodiment, information of
signal charge accumulated in the photoelectric conversion unit PD
is transmitted to the first transparent electrode 62 for each
pixel, and the electric potential that is applied to the first
transparent electrode 62 is determined based on the information.
Accordingly, the transmittance of the dimming control laminated
film 67 can be changed for each pixel, and therefore, the image
quality having higher accuracy can be acquired.
[0155] In addition, advantages that are similar to those of the
first to fourth embodiments can be acquired.
[0156] In this exemplary embodiment, although an example has been
described in which the first transparent electrode 62 is formed for
each photoelectric conversion unit PD in correspondence with the
photoelectric conversion unit PD of each pixel, an example may be
employed in which the first transparent electrode is formed in
correspondence with each pixel row. FIG. 23 illustrates the
relation between first transparent electrode 63 that are formed in
correspondence with the photoelectric conversion unit PD for each
column and the accumulated charge detecting circuit 41 connected
thereto as a modified example of the solid-state imaging device 60
of this exemplary embodiment.
[0157] In the example illustrated in FIG. 23, for each column of
the photoelectric conversion units PD arranged in R, G, and B, the
first transparent electrode 63 is formed, and each first
transparent electrode 63 is formed in each column in a size for
completely covering the corresponding photoelectric conversion
units PD. In addition, the accumulated charge detecting circuit 41
connected to the photoelectric conversion units PD formed for each
column is connected to the first transparent electrode 63
corresponding to each photoelectric conversion unit PD.
[0158] According to this exemplary embodiment, information of
signal charge accumulated in the photoelectric conversion units PD
for each column is transmitted to the first transparent electrode
63 for each pixel row, and the electric potential that is applied
to the first transparent electrode 63 is determined based on the
information. Accordingly, the transmittance of the dimming control
laminated film 67 can be changed for each pixel row.
[0159] As above, the examples of the patterning of the first
transparent electrodes are not limited to each pixel or each pixel
row, and various changes can be made therein.
[0160] FIG. 24 is a configuration diagram in a case where the first
transparent electrodes 64 are formed irregularly with respect to
the pixel area 48 in this exemplary embodiment. In FIG. 24, opening
portions 64a are irregularly formed with respect to the first
transparent electrodes 64, and, in a portion corresponding to each
opening portion 64a, a dimming control laminated film is not
configured. As above, a configuration may be employed in which the
irregular opening portions 64a are formed in the first transparent
electrodes 64 so as to improve the characteristics of pixels.
[0161] In this exemplary embodiment, the patterning of the first
transparent electrodes 62 may be variously changed. In addition, in
this exemplary embodiment, although an example has been described
in which the second transparent electrode 23 is common to all the
pixels, the second transparent electrode 23 side may be formed so
as to be separated for each pixel or each pixel row as well.
6. Sixth Embodiment
Solid-State Imaging Device
[0162] Next, a solid-state imaging device according to a sixth
embodiment of the present disclosure will be described. FIG. 25 is
a schematic cross-sectional view illustrating the configuration of
a main portion of a solid-state imaging device 70 according to this
exemplary embodiment. The solid-state imaging device 70 of this
exemplary embodiment is an example in which the dimming control
laminated film is formed only for green pixels in the fourth
embodiment.
[0163] As illustrated in FIG. 25, in the solid-state imaging device
70 according to this exemplary embodiment, the dimming control
laminated film 77 is configured by a laminated film that is formed
from a first transparent electrode 72, a dimming control layer 74,
a solid electrolyte layer 75, and an ion storing layer 76 and a
second transparent electrode 73. In such as the material of the
dimming control laminated film 77, the same material as that of the
dimming control laminated film 27 in the fourth embodiment can be
used. In this exemplary embodiment, the dimming control laminated
film 77 is formed only in a lower layer of a green color filter
layer 34.
[0164] To the first transparent electrode 72 that configures the
dimming control laminated film 77, an accumulated charge detecting
circuit 41 of the photoelectric conversion unit PD corresponding to
the pixel is connected.
[0165] In addition, according to this exemplary embodiment, in a
pixel in which the dimming control laminated film 77 is not formed,
in the upper portion of a wiring layer 36, a resin layer 71 that
transmits light is formed to be embedded so as to embed a level
difference of the dimming control laminated film 77. As the
material of the resin layer 71, a polystyrene-system resin or an
acrylic resin may be used. Accordingly, a height difference between
a portion in which the dimming control laminated film 77 is formed
and a portion in which the diming control laminated film 77 is not
formed is decreased, whereby the face on which the color filter
layer 34 is formed is flattened.
[0166] FIG. 26 is a diagram illustrating the relation between the
first transparent electrode 72 of the solid-state imaging device 70
according to this exemplary embodiment that is formed in
correspondence with the photoelectric conversion unit PD for each
pixel and the accumulated charge detecting circuit 41 connected
thereto. In the solid-state imaging device 70 according to this
exemplary embodiment, pixels of RGB are arranged in a Bayer array,
and, on the upper portion of only one photoelectric conversion unit
PD(G2) out of two photoelectric conversion units PD(G1) and PD(G2)
that performs photoelectric conversion of green light, the first
transparent electrode 72 is formed. In addition, in the other
pixels, the photoelectric conversion units PD are open.
Furthermore, the first transparent electrode 72 that covers only
the photoelectric conversion unit PD (G2) is electrically connected
to the entire face of the pixel area.
[0167] Although the second transparent electrode 73 is not
illustrated in the figure, it is configured in the same shape as
that of the first transparent electrode 72. The second transparent
electrode may be formed so as to cover the entire face of the pixel
area, and the shape thereof may be variously changed.
[0168] According to the solid-state imaging device 70 of this
exemplary embodiment, since the transmittance of the dimming
control laminated film 77 is changed in one green pixel, a
high-sensitive green pixel and a low-sensitive green pixel can be
disposed, whereby the dynamic range is magnified. As in this
exemplary embodiment, by changing not the exposure time but the
sensitivity, the dynamic range is magnified, whereby an artifact
that remains when a moving subject is photographed can be
prevented.
[0169] In addition, advantages that are similar to those of the
first to fifth embodiments can be acquired.
7. Seventh Embodiment
Solid-State Imaging Device
[0170] Next, a solid-state imaging device according to a seventh
embodiment of the present disclosure will be described. FIG. 27 is
a schematic cross-sectional view illustrating the configuration of
a main portion of a solid-state imaging device 80 according to this
exemplary embodiment. The solid-state imaging device 80 of this
exemplary embodiment is an example in which a liquid crystal layer
is used as the dimming control reacting material of the dimming
control laminated film 27 in the solid-state imaging device 50
according to the fourth embodiment. In FIG. 27, the same reference
numeral is assigned to a portion corresponding to FIG. 18, and
duplicate description thereof will not be repeated.
[0171] In the dimming control laminated film 85 of this exemplary
embodiment, the liquid crystal layer 84 is formed between a first
transparent electrode 22 and a second transparent electrode 23. In
addition, on the sides of the first transparent electrode 22 and
the second transparent electrode 23 that are brought into contact
with the liquid crystal layer 84, oriented films 81 and 82 that
determine the orientation of the liquid crystal are formed.
[0172] As the liquid crystal that configures the liquid crystal
layer 84, a liquid crystal that is commonly used can be used. The
orientation is changed in accordance with an electric potential
applied between the first transparent electrode 22 and the second
transparent electrode 23. Since the transmittance is changed by
changing the orientation of the liquid crystal layer 84, light
transmitted through the photoelectric conversion unit PD can be
adjusted.
[0173] Also in this embodiment, the transmittance of the dimming
control laminated film 85 is changed based on a signal accumulated
in the photoelectric conversion unit PD. Accordingly, the dynamic
range is magnified, and advantages similar to those of the first to
sixth embodiments can be acquired.
[0174] In addition, also in this exemplary embodiment, as
illustrated in FIGS. 22, 23, and 26, the first transparent
electrodes 22 may be formed so as to be separated for each pixel,
for each pixel row, or the like, and various changes can be made
therein.
8. Eighth Embodiment
Solid-State Imaging Device
[0175] Next, a solid-state imaging device according to an eighth
embodiment of the present disclosure will be described. FIG. 28 is
a schematic cross-sectional view illustrating the configuration of
a main portion of a solid-state imaging device 90 according to this
exemplary embodiment. The solid-state imaging device 90 of this
exemplary embodiment is an example in which a photoelectric
conversion layer 94 that includes an organic photoelectric
conversion film 91 is formed on an upper portion of an on-chip lens
35. In FIG. 28, the same reference numeral is assigned to a portion
corresponding to FIG. 17, and duplicate description thereof will
not be repeated.
[0176] As illustrated in FIG. 28, according to the solid-state
imaging device 90 of this exemplary embodiment, the photoelectric
conversion layer 94 is formed on the upper portion of the on-chip
lens 35 through a flattening film 37. The photoelectric conversion
layer 94 is configured by an organic photoelectric conversion film
91 and first and second transparent electrodes 92 and 93 that hold
the organic photoelectric conversion film 91 therebetween. At this
time, the direction of stacking of the first transparent electrode
92, the organic photoelectric conversion film 91, and the second
transparent electrode 93 are configured to be the incident
direction of light, and the photoelectric conversion layer 94 is
formed on the entire face of the pixel area of the solid-state
imaging device 90.
[0177] The first and second transparent electrodes 92 and 93 have a
configuration that is similar to that of the transparent electrodes
of the second embodiment. In addition, according to this exemplary
embodiment, the first transparent electrodes 92, similarly to the
case illustrated in FIG. 22, are formed so as to be separated for
each pixel, and the second transparent electrode 93 is formed so as
to be common to the entire face of the pixel area.
[0178] In addition, the organic photoelectric conversion film 91 is
configured by using a material that can be photoelectrically
converted in accordance with light of green and is formed by using
an organic material such as rhodamine-based dye, merocyanine-based
dye, or quinacridone.
[0179] Furthermore, in this embodiment, a color filter layer 34
that transmits light of red (R) and a color filter layer 34 that
transmits light of blue (B) are alternately arranged.
[0180] In the solid-state imaging device 90 of this exemplary
embodiment, since the photoelectric conversion layer 94 that can
perform photoelectric conversion of green light is formed on the
upper portion of the on-chip lens 35, the green light is
photoelectrically converted by the organic photoelectric conversion
film 91. Accordingly, signal charge corresponding to the green
light is output from the first and second transparent electrodes 92
and 93. The red light and blue light transmitted through the
photoelectric conversion layer 94 are incident through the color
filter layer 34 of each pixel and are photoelectrically converted
by the photoelectric conversion unit PD formed from a photodiode
inside the substrate 30. In other words, according to the
solid-state imaging device 90 of this exemplary embodiment, green
light having a middle wavelength is configured to be acquired by
the organic photoelectric conversion film 91, and blue light having
a short wavelength and red light having a long wavelength are
configured to be acquired by the photoelectric conversion unit PD
located inside the substrate 30.
[0181] In addition, according to the solid-state imaging device 90
of this exemplary embodiment, since the first and second
transparent electrodes 92 and 93 are configured by using
film-shaped graphene that has openings, the transmittance can be
configured to be higher than that of a case where the transparent
electrode in the related art such as ITO is used. Accordingly, the
sensitivity is improved. Furthermore, according to the solid-state
imaging device 90 of this exemplary embodiment, a signal of green
light can be acquired by the photoelectric conversion layer 94 that
is located on the upper portion of the substrate 30, and signals of
the other colors can be acquired by the substrate 30, whereby the
use efficiency of light is improved.
[0182] In this exemplary embodiment, since green light having a
middle wavelength is configured to be photoelectrically converted
by the organic photoelectric conversion film 91, red light and blue
light that is photoelectrically converted inside the substrate 30
have the wavelength regions separated away from each other, whereby
a mixed color can be reduced. In this embodiment, an example has
been described in which green light is photoelectrically converted
by the organic photoelectric conversion film 91, red light or blue
light other than the green light may be configured to be
photoelectrically converted by the organic photoelectric conversion
film 91. Such a case can be realized by changing the material of
the organic photoelectric conversion film 91.
[0183] In addition, as examples of the material of the organic
photoelectric conversion film 91, there are pentacene and
derivatives thereof (TIPS-pentacene and the like), naphthacene and
derivatives thereof (rubrene and hexapropylnaphthacene), thiophene
and derivatives thereof (for example, P3HT and the like), fullerene
and derivatives thereof (PCMB and the like), TCNQ, perylene and
derivatives thereof, porphyrin and derivatives thereof, acridine
and derivatives thereof, coumarin and derivatives thereof,
quinacrodone and the derivatives thereof, cyanine and derivatives
thereof, square lyrium and derivatives thereof, oxazine and
derivatives thereof, T hexane triphenylamine and derivatives
thereof, bezidine and derivatives thereof, pyrazoline and
derivatives thereof, steel amine and derivatives thereof, hydrazine
and derivatives thereof, tiphenylmethane and derivatives thereof,
carbazole and derivatives thereof, polysilane and derivatives
thereof, thiophene and derivatives thereof, polyamine and
derivatives thereof, oxadiazole and derivatives thereof, triazole
and derivatives thereof, triazine and derivatives thereof,
quinozaline and derivatives thereof, phenanthroline and derivatives
thereof, quinolone aluminum and derivatives thereof,
polyparaphenylene vinylene and derivatives thereof, polyfluorene
and derivatives thereof, polyvinylcarbazole and derivatives
thereof, polythiol and derivatives thereof, polypyrrole and
derivatives thereof, and polythiophene and derivatives thereof.
Among the organic materials represented as above, by selecting
materials having peak sensitivity in the wavelength regions of red
(R), green (G), and blue (B), the photoelectric conversion layer
that configures the RGB can be configured. In addition, by using
any organic material represented as above as a single material, the
organic photoelectric conversion film 91 may be formed, or two or
more kinds of the organic materials represented as above may be
mixed or stacked so as to form the organic photoelectric conversion
film 91.
[0184] As above, although the solid-state imaging devices according
to the first to eighth embodiments are configured to detect the
amount of incident light of visible light, the present disclosure
is not limited to being applied to a solid-state imaging device
that captures an image by detecting the distribution of the amount
of incident light of visible light. Other than that, the present
disclosure can be also applied to a solid-state imaging device that
captures the distribution of the amount of incident light of
infrared light, X rays, particles, or the like as an image.
Furthermore, the present disclosure can be applied to the overall
solid-state imaging devices (physical amount distribution detecting
devices) such as a fingerprint detecting sensor that captures an
image by detecting the distribution of another physical amount such
as pressure, electrostatic capacitance, or the like in the broadest
meaning.
[0185] In the above-described exemplary embodiments, the second
area is configured as a gap (opening). However, for example, in the
transparent electrode 14 illustrated in FIG. 3, the second area may
be configured by (for example, filled with) a certain light
transmitting material.
[0186] In addition, in a case where the second area is configured
by a material having optical transparency, the material filled in
the second area may protrude upward from the front face (graphene
face) of the first area. Furthermore, the same material as that
filled in the second area may overlap the whole or a part of the
front face of the first area. For example, a convex-shaped second
area or a second area protruding from the front face of the first
area can be formed by, after an opening is arranged in the
graphene, filling a resin in the opening so as to form the front
face in the shape of a semicircle and slightly protrude from the
first area and hardening the resin in the state.
[0187] Here, it is preferable that the second area is configured by
using a material that has light transmittance higher than the light
transmittance of the graphene as a single layer, and, for example,
it is preferable that the second area is filled with a graphene
oxide, a transparent polymer material, or the like. As examples of
the transparent polymer material, there are polyethylene,
polypropylene, polyethylene terephthalate, polystyrene, ABS resin,
acryl, polyamide, polycarbonate, fluorinated resin, phenol resin,
melamine, epoxy, and the like.
[0188] As described above, in a case where the second area of the
transparent electrode 14 is configured by using a material having
light transmittance higher than that of the graphene as a single
layer, the light transmittance of the second area is higher than
that of the first area. Accordingly, the light transmittance of the
whole transparent electrode 14 is higher than that of the graphene
as a single layer.
[0189] In addition, in a case where the transparent electrode is
configured by stacking sheets formed from a plurality of graphenes,
it is preferable that the second areas of each layer are laid out
so as not to confront each other. By shifting the second areas of
the graphenes of the upper and lower layers, for example, the
openings from each other, the whole transmittance can have
uniformity.
[0190] Furthermore, as the solid-state imaging device according to
the first embodiment, although the CCD-type solid-state imaging
device has been described as an example, a CMOS-type solid-state
imaging device may be used. In addition, the solid-state imaging
devices according to the second to eighth embodiments may be
CCD-type solid-state imaging devices or CMOS-type solid-state
imaging devices. Furthermore, in the solid-state imaging devices
according to the first to eighth embodiments, although an example
has been described in which the wiring layer is formed on the light
emission side of the substrate, the configuration according to an
embodiment of the present disclosure can be also applied to a
rear-face emission-type solid-state imaging device in which the
wiring layer is formed on a side opposite to the light emission
side.
[0191] In addition, the present disclosure is not limited to the
solid-state imaging device that reads out a pixel signal from each
unit pixel by scanning each unit pixel of the pixel area in units
of rows. Thus, an embodiment of the present disclosure can be
applied also to a solid-state imaging device of the X-Y address
type that selects an arbitrary pixel in units of pixels and reads
out signals in units of pixels from the selected pixel.
[0192] Furthermore, the solid-state imaging device may have a form
that is formed as one chip or a module-shaped form having an
imaging function in which a pixel area and a signal processing unit
or an optical system are arranged so as to be packaged.
[0193] In addition, the present disclosure is not limited to being
applied to the solid-state imaging device but may be applied to an
imaging apparatus. Here, the imaging apparatus is a camera system
such as a digital still camera or a video camera or an electronic
apparatus such as a cellular phone that has an imaging function.
Furthermore, there is a case where a form in the module shape that
is mounted in an electronic apparatus, in other words, a camera
module may be configured as an imaging apparatus.
9. Ninth Embodiment
Electronic Apparatus
[0194] Next, an electronic apparatus according to a ninth
embodiment of the present disclosure will be described. FIG. 29 is
a schematic configuration diagram of an electronic apparatus 100
according to the ninth embodiment of the present disclosure.
[0195] The electronic apparatus 100 according to this embodiment
includes a solid-state imaging device 103, an optical lens 101, an
aperture diaphragm 106, a shutter device 102, a driving circuit
105, and a signal processing circuit 104. The electronic apparatus
100 of this exemplary embodiment represents an embodiment in a case
where the solid-state imaging device 1 according to the first
embodiment of the present disclosure as the solid-state imaging
device 103 is used in an electronic apparatus (camera).
[0196] The optical lens 101 images image light (incident light)
transmitted from a subject on an imaging surface of the solid-state
imaging device 103. Accordingly, signal charge is accumulated
inside the solid-state imaging device 103 for a predetermined time.
The aperture diaphragm 106 adjusts the brightness by controlling
light beams. The shutter device 102 controls the light emitting
period and the light shielding period for the solid-state imaging
device 103. The driving circuit 105 supplies a driving signal that
is used for controlling the transfer operation of the solid-state
imaging device 103, the operation of the aperture diaphragm 106,
and the shutter operation of the shutter device 102. The
solid-state imaging device 103 performs signal transmission in
accordance with the driving signal (timing signal) that is supplied
from the driving circuit 105. The signal processing circuit 104
performs various signal processing. A video signal for which the
signal processing has been performed is stores in a storage medium
such as a memory or is output to a monitor.
[0197] According to the electronic apparatus 100 of this exemplary
embodiment, the dynamic range of the solid-state imaging device 103
is magnified so as to improve the image quality.
[0198] The electronic apparatus 200 to which the solid-state
imaging device 1 can be applied is not limited to a camera but can
be applied to a digital still camera, an imaging apparatus such as
a mobile device camera module of a cellular phone or the like.
[0199] In this exemplary embodiment, although the solid-state
imaging device 1 according to the first embodiment is configured to
be used in an electronic apparatus as the solid-state imaging
device 103, any of the solid-state imaging devices manufactured
according to the second to eighth embodiments can be used.
[0200] The dimming control laminated film built in the solid-state
imaging devices according to the above-described second to eighth
embodiments may be used in a shutter device Or an aperture
diaphragm of the electronic apparatus. Hereinafter, an example will
be illustrated in which the dimming control laminated film is used
as each unit configuring the electronic apparatus.
10. Tenth Embodiment
Electronic Apparatus
[0201] Next, an electronic apparatus according to a tenth
embodiment of the present disclosure will be described. FIG. 30 is
a schematic configuration diagram of an electronic apparatus 200
according to this exemplary embodiment. The electronic apparatus
200 of this exemplary embodiment is an example in which the dimming
control laminated film 227 is used as the aperture diaphragm 203.
In FIG. 30, to a portion corresponding to that illustrated in FIG.
29, the same reference numeral is assigned, and duplicate
description thereof will not be presented.
[0202] In the electronic apparatus 200 of this exemplary
embodiment, a dimming control laminated film 227 that configures
the aperture diaphragm 203 is formed in a course between the
optical lens 101 and the shutter device 102. The dimming control
laminated film 227 is configured by a laminated film that is formed
from a dimming control layer 224, a solid electrolyte layer 225,
and an ion storing layer 226 and first and second transparent
electrodes 222 and 223 that hold them therebetween. At this time,
the direction of stacking the first transparent electrode 222, the
dimming control layer 224, the solid electrolyte layer 225, the ion
storing layer 226, and the second transparent electrode 223 is
configured to be the incidence direction of light.
[0203] In addition, in this exemplary embodiment, as the
solid-state imaging device 103, any of the solid-state imaging
devices according to the first to eighth embodiments may be used or
a general solid-state imaging device may be used. Thus, in this
exemplary embodiment, the configuration of the solid-state imaging
device 103 is not particularly limited.
[0204] Also in this embodiment, the first transparent electrode 222
and the second transparent electrode 223, similarly to the first
and second embodiments, are configured by film-shaped graphene
having an opening and can be formed similarly to the first
embodiment. In addition, as the materials of the dimming control
layer 224, the solid electrolyte layer 225, and the ion storing
layer 226, the same materials as those of the second embodiment can
be used. In addition, in this exemplary embodiment, the dimming
control laminated film 227 is formed in a circular shape.
[0205] The first transparent electrode 222 and the second
transparent electrode 223 are configured to be supplied with
desired electric potentials based on signals transmitted from the
driving circuit 105, and the electric potentials are applied to the
first transparent electrode 222 and the second transparent
electrode 223 in a circular shape. By supplying the electric
potentials between the first transparent electrode 222 and the
second transparent electrode 223 in a circular shape, the
transmittance of the aperture diaphragm 203 sequentially decreases
from the circumferential edge, and the opening diameter of the
diaphragm through which light is transmitted is changed.
Accordingly, the opening diameter of the aperture diaphragm 203
changes.
[0206] However, in order to supply the electric potentials between
the first and second transparent electrodes 222 and 223 in the
circular shape, it may be configured such that at least one
transparent electrode is configured to be separated into multiple
parts in concentric shapes, and the electric potential is
sequentially supplied from the transparent electrode that is formed
on the outer side. Accordingly, the dimming control laminated film
227 can be used as an electrical iris system, and the transmittance
thereof changes in accordance with an applied voltage.
[0207] In this exemplary embodiment, since the aperture diaphragm
203 is configure by the dimming control laminated film 227, the
edge (a boundary between a portion having high transmittance and a
portion having low transmittance) of the aperture diaphragm 203 is
soft, whereby the iris can minimize the image artifact due to the
diffraction of the aperture diaphragm.
11. Eleventh Embodiment
Electronic Apparatus
[0208] Next, an electronic apparatus according to an eleventh
embodiment of the present disclosure will be described. FIG. 31 is
a schematic configuration diagram of the electronic apparatus
according to this exemplary embodiment. An electronic apparatus 300
of this exemplary embodiment is an example in which a dimming
control laminated film 327 is used as a shutter device 302. In FIG.
31, to a portion corresponding to that illustrated in FIG. 29, the
same reference numeral is assigned, and duplicate description
thereof will not be presented.
[0209] According to the electronic apparatus 300 of this exemplary
embodiment, a dimming control laminated film 327 that configures
the shutter device 302 is arranged in an optical path of light
incident through an optical lens 101 and the aperture diaphragm
106, and the incident light is configured to be incident on the
solid-state imaging device 103 through the shutter device 302. The
shutter device 302 is configured by a laminated film that is formed
from a dimming control layer 324, a solid electrolyte layer 325,
and an ion storing layer 326 and first and second transparent
electrodes 322 and 323 that hold them therebetween. At this time,
the direction of stacking the first transparent electrode 322, the
dimming control layer 324, the solid electrolyte layer 325, the ion
storing layer 326, and the second transparent electrode 323 is
configured to be the incidence direction of light.
[0210] Also in this embodiment, the first transparent electrode 322
and the second transparent electrode 323 are configured by
film-shaped graphene having an opening, and the transparent
electrodes can be formed similarly to the first embodiment. In
addition, as the materials of the dimming control layer 324, the
solid electrolyte layer 325, and the ion storing layer 326, the
same materials as those of the second embodiment can be used.
[0211] The first transparent electrode 322 and the second
transparent electrode 323 are configured to be supplied with
desired electric potentials from the driving circuit 105 at timing
that is based on the shutter speed. By supplying the desired
electric potentials between the first transparent electrode 322 and
the second transparent electrode 323, the light transmittance can
be adjusted. Accordingly, at the time of exposure, light is
transmitted with high transmittance, and, at the time of shielding
light, light can be shielded with high light shielding rate. As in
this exemplary embodiment, by using the dimming control laminated
film 327 as the shutter device, a moving mechanism having a large
scale is not necessary, whereby a decrease in size can be
achieved.
[0212] In addition, in this embodiment, since the first and second
transparent electrodes 322 and 323 configuring the dimming control
laminated film 327 are configured by using film-shaped graphene
having an opening, the maximum transmittance is higher than that of
the transparent electrode that is formed from ITO. In addition, by
changing the aperture ratio of the transparent electrodes, the
transmittance can be changed. Accordingly, sufficient transmittance
can be acquired at the time of exposure.
[0213] In the above-described tenth and eleventh embodiments, the
openings formed in the first and second transparent electrodes used
in the dimming control laminated film are set in accordance with
the performance demanded by the device. In addition, in the
above-described tenth and eleventh embodiments, the dimming control
laminated film is configured to be used in the aperture diaphragm
or the shutter device, by variously setting the shape of the
openings of the transparent electrodes formed from graphene, they
may be used as an apodizing mask.
[0214] As above, in the present disclosure, by using graphene
having an opening as the transparent electrode, the range of the
applications to which the configuration can be applied can be
widened. As described above, in the transparent electrode formed
from ITO in the related art, since the transmittance under light is
90%, it is not practical to use the transparent electrode as a
sensor, a shutter, an aperture diaphragm, or the like. In the
present disclosure, by forming the transparent electrodes used in
the above-described devices by using graphene films having
openings, the transmittance can be increased up to 99% or more,
whereby it can be sufficiently used in the sensor, the shutter, and
the aperture diaphragm described above.
[0215] As above, the embodiments of the present disclosure have
been illustrated as the first to eleventh embodiments, the present
disclosure is not limited to the above-described example, and
various changes can be made therein within a scope not departing
from the concept thereof. In addition, the configurations according
to the first to eleventh embodiments may be configured to be
combined together.
[0216] Furthermore, the present disclosure may be implemented as
the following configurations.
[0217] (1) A solid-state imaging device including: a substrate; a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; and a transparent electrode that is formed in an
upper portion of the substrate and includes a first area formed
from a nano carbon material and a second area that is brought into
contact with the first area and has light transmittance higher than
that of the first area.
[0218] (2) The solid-state imaging device described in (1), wherein
the second area is formed from a gap, graphene oxide, or a
transparent polymer material.
[0219] (3) The solid-state imaging device described in (1) or (2),
wherein the second area is formed from a gap, and an opening
diameter of the gap is smaller than an area of a unit pixel.
[0220] (4) The solid-state imaging device described in any one of
(1) to (3), wherein a width of a narrowest portion of the first
area is larger than 10 nm.
[0221] (5) The solid-state imaging device described in any one of
(1) to (4), wherein a dimming control laminated film that adjusts a
light amount of light incident on a light incident side of the
substrate is formed, and the dimming control laminated film is
configured by a dimming control reacting material layer of which
transmittance changes based on an applied voltage and first and
second transparent electrodes that hold the dimming control
reacting material layer therebetween, and at least one of the first
and second transparent electrodes is configured by the transparent
electrode that is formed from the nano carbon material.
[0222] (6) The solid-state imaging device described in (5), wherein
a color filter layer and an on-chip lens that are formed in order
from the light incident light side of the substrate is further
included, and the dimming control laminated film is arranged to the
light incident side relative to the on-chip lens.
[0223] (7) The solid-state imaging device described in (5), wherein
a color filter layer and an on-chip lens that are formed in order
from the light incident side of the substrate is further included,
and the dimming control laminated film is formed between the
substrate and the color filter layer.
[0224] (8) The solid-state imaging device described in (5), wherein
an accumulated charge detecting circuit that detects signal charge
generated by the photoelectric conversion unit is connected to the
first transparent electrode, and a voltage based on the signal
charge generated by the photoelectric conversion unit is applied to
the fist transparent electrode.
[0225] (9) The solid-state imaging device described in any one of
(5) to (8), wherein the first transparent electrode is formed to be
separated for each predetermined pixel.
[0226] (10) The solid-state imaging device described in any one of
(5) to (8), wherein the dimming control laminated film is formed
only in an upper portion of the photoelectric conversion unit that
corresponds to the predetermined pixel.
[0227] (11) The solid-state imaging device described in any one of
(1) to (10), wherein the transparent electrode is configured by a
single layer or a plurality of layers of a film-shaped nano carbon
material.
[0228] (12) The solid-state imaging device described in any one of
(1) to (11), wherein the transparent electrode is configured by a
plurality of layers of film-shaped nano carbon materials, and the
second areas of each layer are laid out not so as to confront each
other.
[0229] (13) The solid-state imaging device described in any one of
(1) to (12), wherein the gap formed in the transparent electrode is
formed only in an effective pixel area but is not formed in a black
reference pixel area.
[0230] (14) The solid-state imaging device described in any one of
(5) to (13), wherein the dimming control reacting material layer is
configured by an electrochromic material.
[0231] (15) The solid-state imaging device described in any one of
(5) to (13), wherein the dimming control reacting material layer is
configured by a liquid crystal layer.
[0232] (16) The solid-state imaging device described in any one of
(1) to (15), wherein a photoelectric conversion layer that
generates signal charge corresponding to light amount of light
incident on a light incident side of the substrate is formed, and
the photoelectric conversion layer is configured by an organic
photoelectric conversion film that absorbs light of a predetermined
wavelength and first and second transparent electrodes that hold
the organic photoelectric conversion film therebetween, and at
least one of the first and second transparent electrodes is formed
from a nano carbon material.
[0233] (17) The solid-state imaging device described in any one of
(1) to (16), wherein the nano carbon material is graphene.
[0234] (18) The solid-state imaging device described in any one of
(1) to (17), wherein a desired additive is added to the transparent
electrode.
[0235] (19) An electronic apparatus including: an optical lens; a
solid-state imaging device that includes a substrate, a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light, a transparent electrode that is formed in an upper
portion of the substrate, formed from a nano carbon material and
has a plurality of openings, and to which light collected to the
optical lens is incident; and a signal processing circuit that
processes an output signal output from the solid-state imaging
device.
[0236] (20) An electronic apparatus including: an optical lens; a
solid-state imaging device that includes a substrate and a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; an aperture diaphragm that is formed in an optical
path between the optical lens and the solid-state imaging device,
adjusts light beams transmitted from the optical lens, and is
configured by a dimming control reacting material layer of which
transmittance changes based on an applied voltage and first and
second transparent electrodes that hold the dimming control
reacting material layer therebetween; and a signal processing
circuit that processes an output signal output from the solid-state
imaging device. At least one transparent electrode of the first and
second transparent electrodes is configured by a transparent
electrode that is formed from a nano carbon material having a
plurality of openings.
[0237] (21) An electronic apparatus including: an optical lens; a
solid-state imaging device that includes a substrate and a
photoelectric conversion unit that is formed on the substrate and
generates signal charge in correspondence with a light amount of
incident light; a shutter device that is formed in an optical path
between the optical lens and the solid-state imaging device,
controls an exposure time toward the photoelectric conversion unit,
and is configured by a dimming control reacting material layer of
which transmittance changes based on an applied voltage and first
and second transparent electrodes that hold the dimming control
reacting material layer therebetween; and a signal processing
circuit that processes an output signal output from the solid-state
imaging device. At least one transparent electrode of the first and
second transparent electrodes is configured by a transparent
electrode that is formed from a nano carbon material having a
plurality of openings.
[0238] The present disclosure contains subject matter related to
those disclosed in Japanese Priority Patent Applications JP
2011-072177 and JP 2011-271364 filed in the Japan Patent Office on
Mar. 29, 2011 and Dec. 12, 2011, respectively, the entire contents
of which are hereby incorporated by reference.
[0239] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
* * * * *